You're right that this one thing alone doesn't spell addiction, but if someone talked about how they should use the bathroom less, felt bad about how many times a day they went, and annoyed everyone by the bathroom constantly being occupied and the person being absent/late due to their use, in addition to using it first thing in the morning, then... maybe they're addicted to social media and using the bathroom as a way to get their fix ;)
Thanks for sharing that link. The test seems to be setting the bar pretty darn low, however. It's enough that you think you should be doing less of something, and others have criticized you about it to the point of annoying you. That includes things I would put in the category of bad habits rather than clinically actionable disorders.
Is "eating" the first thing you do in the morning? Would it be ok to leave a sandwich in the table next to the bed to take a bite as soon as you wake up?
Of course this is a matter of opinion. I don't want to get too picky about the details. I used to wake up and check Facebook right away, and I considered it not to be really healthy. But again, just my preference.
Here's another way to put it - "If the first thing a person does when they get up is eat, you'd say they're a glutton". True?
(Or indeed "if the first thing a person does when they get up is go to the toilet, you'd say they're incontinent.")